Optical fiber unit for medical examination and treatment and arm device for the optical fiber

ABSTRACT

An optical fiber unit for medical examination and treatment according to the invention has an object of not requiring a light condensing lens group by tapering the tip end side of the optical fiber light guide. Optical fiber light guide  1  has flexibility and guides light including infrared rays emitted from a light source to probe  4  which is located at the tip end thereof, through a flexible guide tube  3.  The tapered conduit part  5,  the diameter of which is made smaller toward the tip end thereof condenses the light and allows the same to be emitted from the tip end plane of the probe  4.  The rectilinear polarization plate  8  rectilinearly polarizes light including infrared rays emitted from the tip end plane of the tapered conduit part  5  and irradiates the same onto an affected part.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to an optical fiber unit for medicalexamination and treatment and arm device for the optical fiber. Inparticular, the invention relates to an optical fiber unit for medicalexamination and treatment which is able to cure or treat an affectedpart by a heating effect, etc. by irradiating infrared rays to theaffected part, and an arm device for the optical fiber which is able toretain the optical fiber unit so as to easily operate the same.

Conventionally, this kind of optical fiber unit for medical examinationand treatment was such that, like an optical fiber unit for medicalexamination and treatment disclosed, for example, in Japanese UtilityModel Publication No. 27172 of 1994, light including infrared raysemitted from a light source was guided through an optical fiber lightguide, condensed by a light condensing lens group and irradiated onto anaffected part.

Furthermore, a conventional arm device for optical fibers is formed sothat the two arm parts thereof are formed of two or three joint parts,and when an optical fiber unit to which the arm device is attached isoperated, the arm device flexes or turns, following the operationthereof, thereby causing the operation of the optical fiber unit to beimproved.

Since the abovementioned optical fiber unit for medical examination andtreatment was constructed so that infrared rays emitted from a lightsource were guided through a fiber light guide, condensed by a lightcondensing lens group and irradiated onto an affected part, a lightcondensing lens group was an indispensable factor due to its precisionas an optical component. Such structure is disadvantageous in that theproduction cost was increased, and the assembling thereof was not madeeasy.

Furthermore, the conventional arm device for optical fibers have two armparts of a fixed length. This caused further problems in that they wereinsufficiently flexible, did not adapt themselves to the operatingenvironments, and an excessive load is applied to the joint parts due togravity when the arm part was elongated in the horizontal direction,resulting in a posture that could not be kept constant.

OBJECTS AND SUMMARY OF THE INVENTION

In view of the abovementioned points, it is therefore an object of theinvention to provide an optical fiber unit for medical examination andtreatment in which no light condensing lens group is required by makingthe tip end part of the optical fiber light guide a tapered conduitpart, the diameter of which is gradually made smaller toward the tip endthereof.

Another object of the invention is to provide an arm device for theoptical fiber, having flexible arm parts and a joint part which can belocked in one direction, and which is able to adapt itself to theoperating environments of the optical fiber unit and to keep the posturethereof constant with the arm parts thereof elongated in the horizontaldirection.

An optical fiber unit for medical examination and treatment according tothe invention, and which treats or cures an affected part by irradiatinglight including infrared rays emitted from a light source onto theaffected part through a flexible optical fiber light guide, ischaracterized in that the tip end side of the optical fiber light guideconsists of a tapered conduit part, the diameter of which is madesmaller toward the tip end thereof, whereby the tapered conduit partcondenses light including the infrared rays and irradiates the same tothe affected part.

According to an optical fiber unit for medical examination and treatmentof the invention, since the tip end part of the optical fiber lightguide is made a tapered conduit part and no light condensing lens groupis required, there are effects by which the production cost of thedevice can be decreased by elimination of expensive optical components,and the assembling thereof can be made easier.

Furthermore, an arm device for an optical fiber according to theinvention is characterized in having a base part fixed at the lightsource main body, a first joint part which is rotatable around the shaftof the base part and is attached so as to be rockable in one directionvia a one-way clutch in the perpendicular plane with respect to therotating plane, a first flexible arm part flexibly attached to the firstjoint part, a second joint part which is rotatable around the shaft ofthe first flexible arm part and is attached so as to be rockable in onedirection via a one-way clutch in the perpendicular plane with respectto the rotating plane, a second flexible arm part flexibly attached atthe second joint part, a third joint part rotatably and rockablyattached to the second flexible arm part, and a probe retaining part forretaining a probe of an optical fiber unit attached to the third jointpart.

Since an arm device for optical fiber according to the invention isprovided with two flexible arm parts, two joint parts having a one-wayclutch, and one joint part having a universal joint, it is possible tomove the probe so as to adapt the arm device to the operatingenvironments of an optical fiber unit, and simultaneously the posture ofthe arm device can be kept constant even though the arm part iselongated in the horizontal direction, whereby there is an effect ofremarkably increasing the operation efficiency of the optical fiberunit.

Furthermore, the first joint part is provided with an operating memberfor cancelling the locking of one-way clutch, thus providing an effectby which the movement of the first flexible arm part toward any optionalinclined position can be further facilitated.

Still furthermore, the second joint part is provided with a guiding partfor insertably nipping a flexible guide tube of the optical fiber unittherebetween, thus providing an effect by which the followability of thearm device for optical fiber to the optical fiber unit can be furtherimproved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view showing an upper cross-section of anoptical fiber unit for medical examination and treatment according to afirst preferred embodiment of the invention.

FIG. 2 is a front elevational view showing an arm device for an opticalfiber according to the first preferred embodiment of the invention.

FIG. 3 is a side elevational view of an arm device for an optical fiberaccording to the preferred embodiment.

FIG. 4 is an enlarged view of the base part and first joint partillustrated in FIG. 2.

FIG. 5 is a cross-sectional view of the first joint part illustrated inFIG. 2.

FIG. 6 is an enlarged side elevational view of the second joint partillustrated in FIG. 2.

FIG. 7 is an enlarged side elevational view of the third joint part andprobe retaining part illustrated in FIG. 2.

FIG. 8 is an enlarged cross-sectional view of the third joint partillustrated in FIG. 2.

FIG. 9 is an enlarged side elevational view of the probe retaining partillustrated in FIG. 2.

FIG. 10 is an enlarged side elevational view showing a modified exampleof the first joint part illustrated in FIG. 2.

FIG. 11 is a cross-sectional view of a modified example of the firstjoint part illustrated in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a side elevational view showing an upper cross-section of themajor parts of an optical fiber unit for medical examination andtreatment according to the first preferred embodiment of the invention.The principal part of the optical fiber unit for medical examination andtreatment according to the preferred embodiment consists of opticalfiber light guide 1, protection pipe 2, flexible guide tube 3, probe 4,tapered conduit part 5 and tip end cap 6.

The optical fiber light guide 1 is of a quartz-orientedmulti-constituent structure in which about 19,000 optical fibersconsisting of cores having different refraction indexes and claddingsare bundled. The diameter of each single fiber is 50 μm or so.Furthermore, optical fiber light guide 1 does not allow any transmissionof infrared rays of a long wavelength band of 1.6 μm or more.

The protection pipe 2 is a pipe made of aluminum, etc., which protectsthe base part of optical fiber light guide 1.

The flexible guide tube 3 has optical fiber light guide 1 insertedtherein and is provided to protect the light guide by surrounding it sothe optical fiber light guide does not bend beyond a certain limit.

The probe 4 is fixed at the tip end part of the optical fiber lightguide 1 and is a part which is operated by being nipped by a user'sfingers or an arm device. The diameter of probe 4 is gradually madesmaller toward the tip end side thereof in line with the tapered conduitpart 5, wherein a male screw onto which a tip end cap 6 is screwed isthreaded on the outer circumference of the tip end part.

The tapered conduit part 5 is a hard part formed to be gradually madesmaller toward the tip end part thereof by heating and elongating thetip end part of optical fiber light guide 1. The tapered conduit part 5takes a role of condensing light emitted from the base end plane ofoptical fiber light guide 1 to a light flux having a circularcross-section, which is approximate to a parallel light flux.

The tip end cap 6 is constructed so as to be detachably screwed onto thetip end part of probe 4 via a female screw threaded on the interiorthereof, wherein and includes spring 7, rectilinear polarization plate8, sleeve 9 and cover glass 10 disposed therein arranged one afteranother.

The rectilinear polarization plate 8 is formed by a process in whichfilm-like polyvinyl alcohol is dyed with an iodine solution andsandwiched by optical glass plates at both the inside and outsidethereof. The rectilinear polorization plate 8 serves to straighten thelight polarization plane of a wavelength band of 0.6 to 1.6 μm or thelike. Furthermore, it is known that rectilinearly polarized infraredrays have remarkable effects in activating biopolymers and improvingminute circulations and further increase the curing effects.

Next, a description is given of the use of an optical fiber unit formedical examination and treatment according to the preferred embodimentconstructed as described above.

Light including infrared rays emitted from a light source (notillustrated) is irradiated into the base end plane of optical fiberlight guide 1.

The optical fiber light guide 1 cuts off the infrared rays of a longwavelength band of 1.6 μm or more and may allow light of otherwavelength bands to pass therethrough. The passed light reaches the tipend side while being reflected by cladding in the cores of therespective optical fibers, is gradually condensed at the tapered conduitpart 5 and is caused to exit through the tip end plane.

Light including infrared rays emitted from the tip end plane of theoptical fiber light guide 1 is rectilinearly polarized by a rectilinearpolarization plate 8 and is irradiated onto an affected part through acover glass 10.

At this time, since the optical fiber light guide 1 has flexibility andis made bendable, the infrared rays can be condensed and irradiated tobe spot-like onto an affected part at any position at a high energyconcentration by operating the probe 4.

Light irradiated by an optical fiber unit for medical examination andtreatment onto an affected part has a ratio in which visible light rayswhich are red in color occupy about 5% and the invisible near infraredrays which can be absorbed deeply into the human body to provide aheating effect occupy about 95%. The peak of concentration exists in thevicinity of 1.0 μm. Light of a wavelength band of 0.6 to 1.6 μm or sohas a great biopenetration power by which living tissue located deep inthe body can be heated and activated.

Therefore, an optical fiber unit for medical examination and treatmenthas effects in the indications described below;

(1) Pain

Subacute and chronic pains and neuralgia of muscles and joints

(i) Neck . . . Pain of cervical vertebra, whiplash injury, crick insleep

(ii) Shoulder, back . . . Scalpulohumeral periarthritis, dorsum pain,shoulder joint sprain

(iii) Lumbar region . . . Slipped disk, sciatica, pain due to hernia ofintervertebral disk

(iv) Arm . . . Elbow joint pain, tennis elbow, pollex snapping fingers

(v) Leg . . . Knee joint pain

(2) Inflammatory Pain, Lesion (After the Acute Term)

Pains resulting from sprain, fracture, tendosynovitis, slipped disk,deep muscle injury, ligament injury, and spasm suppression of muscles

(3) Arthritis and Rheumatism

Rheumatic arthritis, ostarthritis deformans (excluding the acute,subacute ostarthritis)

(4) Dermatose

Chronic dermatitis, acnevulgaris, bedsore

FIG. 2 is a front elevational view showing a state where an opticalfiber unit for medical examination and treatment according to theabovementioned preferred embodiment is attached to an arm device foroptical fiber according to one preferred embodiment of the invention.The major part of the arm device for optical fiber according to thepreferred embodiment consists of a base end part 101, a first joint part102, a first flexible arm part 103, a second joint part 104, a secondflexible arm part 105, a third joint part 106, and a probe retainingpart 107.

The base end part 101 is, as shown in enlargement in FIG. 4, composed ofa shaft 111 inserted into and fixed at a light source device main body(not illustrated) of an optical fiber unit for medical examination andtreatment and a cylindrical member 112 into which the shaft 111 isinternally inserted. The lower end plane of the cylindrical member 112is diagonally notched and is fixed at the outward diagonal plane of thelight source device main body so as not to be rotatable.

The first joint part 102 is, as shown in cross-section in FIG. 5,composed of an axial fixing member 121 rotatably attached by a screw 120via a shock absorbing member fitted into the shaft 111 of the base endpart 101 so as to be prevented from slipping off, a bearing member 125rotatably attached to the axial fixing member 121 via a brake shoe 122,an intermediate member 123 and a one-way clutch 124, an axis 128inserted into the bearing member 125 and screwed by a screw 129 at theaxial fixing member 121 via a plate spring 126 and a washer 127, a screw130 screwed into the axial fixing member 121 so as to regulate therotations of the axis 128. With such a construction, it is possible forthe axial fixing member 121 to turn 360 degrees on the horizontal planecentering around the shaft 111 and possible for the bearing member 125to turn about 100 degrees on the perpendicular plane with respect to theaxial fixing member 121. Furthermore, the first flexible arm part 103 islocked by the one-way clutch 124 in the direction along which the firstflexible arm part 103 falls down, whereby no load is given in thedirection of vertically returning the first flexible arm part 103.

As shown in FIG. 3, the first flexible arm part 103 is composed of alower cover 131 fixed at the bearing member 125 of the first joint part102, an outer pipe 132, the lower end of which is inserted into andfixed in the lower cover 131, an inner pipe 133 which is internallyinserted into the outer pipe 132, a locking member 134 secured on theupper end of the outer pipe 132, and an upper cover 135 fixed at thesecond joint part 104, into which the upper end of the inner pipe 133 isinserted and fixed. By operating the locking member 134, the outer pipe132 is fixed with respect to the inner pipe 133 and the first flexiblearm part 103 can be set to any desired length.

As shown in enlargement in FIG. 6, the second joint part 104 isconstructed almost equivalent to the first joint part 102. That is, thesecond joint part 104 is composed of an axial fixing member 141 fittedinto the shaft of the first flexible arm part 103 and rotatably attachedby a screw 140 via a shock absorbing member so as to be prevented fromslipping off, a bearing member 145 rotatably attached to the axialfixing member 141 via a one-way clutch 144, an axis 148 inserted intothe bearing member 145 and screwed by a screw 149 to the axial fixingmember 141 via a plate spring 148 and a washer 147, and a screw 150screwed into the axial fixing member 141 so as to regulate the rotationsof the axis 148. With such a construction, the axial fixing member 141can be turned 360 degrees centering around the shaft of the firstflexible arm part 103 and simultaneously can be turned about 100 degreesin the perpendicular plane with respect to the plane of rotation.Furthermore, the second flexible arm part 105 is locked by the one-wayclutch 144 in the direction along which the second flexible arm part 105falls down, whereby no load is given when moving the second flexible armpart 105 in the horizontal direction.

Furthermore, as shown in FIG. 3 and FIG. 6, a guide part 108 in which aflexible guide tube 3 of an optical fiber unit for medical examinationand treatment is insertably put is secured at a side of the second jointpart 104. The guide part 108 is composed of a fan-shaped plate 181 fixedat the axis 148 of the second joint part 104 and two sets of rollerpairs 182, 183 attached to the fan-shaped plate 181 (See FIG. 2).

The second flexible arm part 105 is constructed almost equivalent to thefirst flexible arm part 103. That is, as shown in FIG. 2, the secondflexible arm part 105 consists of an upper cover 151 fixed at thebearing member 145 of the second joint part 104, an outer pipe 152, theupper end of which is attached to the upper cover 151, an inner pipe 153internally inserted into the outer pipe 152, a locking member 154secured at the lower end of the outer pipe 152, and a lower cover 155fixed at the third joint part 106, into which the lower end of the innerpipe 153 is inserted and fixed. By operating the locking member 154, theouter pipe 152 is fixed at the inner pipe 153 and the second flexiblearm part 105 can be set to any desired length.

As shown in enlargement in FIG. 7, the third joint part 106 is composedof a universal joint base 161 attached to the second flexible arm part105. The universal joint base 161 is, as shown in cross-section in FIG.8, composed of a base 162 which is provided with a threaded hole to befixed at the lower cover 155 of the second flexible arm part 105, afirst cylindrical member 163 which surrounds the base 162, a secondcylindrical member 164 slidably fitted with respect to the firstcylindrical member 163 so as to be prevented from slipping off, atapered member 165 secured in the first cylindrical member 163, asliding member 166 which slides in line with movements of the taperedmember 165, a coil spring 167 which intervenes between the taper member165 and the sliding member 166, a universal joint member 168, theposition of which is fixed in the second cylindrical member 164 by beingpressed by the sliding member 166, a fixing screw 169 which is screwedinto the first cylindrical member 163 to press and move the taperedmember 165, and a knob 170 attached to the fixing screw 169. With such aconstruction, as the fixing screw 169 is screwed by operating the knob170 after operating the universal joint member 168 in a desireddirection, the tapered member 165 moves to cause the sliding member 166to slide against the resiliency of the coil spring 167, whereby theuniversal joint member 168 is pressed and fixed in the secondcylindrical member 164.

As shown in enlargement in FIG. 7, the probe retaining part 107 iscomposed of a gripping part 171 attached to the universal joint base161. The gripping part 171 is, as shown in cross-section in FIG. 9,composed of a base 172 screwed to the tip end of the universal jointmember 168 of the universal joint base 161, a fixing screw 173 by whichthe base 172 is fixed at the universal joint member 168, a pair ofgripping members 174, 175 attached to the base 172, a sliding axis 176secured so as to pass through the pair of gripping members 174, 175, anut 177 which fixes one end of the sliding axis 176, a knob 178 attachedto the other end of the sliding axis 176, and a coil spring 179 whichpresses the sliding axis 176. With such a construction, the probe 4 ofan optical fiber unit for medical examination and treatment is insertedbetween the gripping members 174, 175 with the gripping members 174, 175slackened by operating the knob 178. Thereafter, by operating the knob178, the sliding axis 176 is caused to move against the coil spring 179,thereby causing the clearance between the gripping members 174, 175 tobe made narrow. Therefore, the probe 4 is retained at the gripping part171. Furthermore, the probe retaining part 107 can be turned 360 degreeswith respect to the center of the universal joint base 161 and can beinclined about 120 degrees.

Next, a description is given of how to use an arm device for opticalfiber according to the preferred embodiment constructed as describedabove.

First, a user of an optical fiber unit for medical examination andtreatment inserts the shaft 111 of the base end part 101 into its fixinghole (not illustrated) drilled at the light source device main body andattaches an arm device for optical fiber to the light source device mainbody. Next, a flexible guide tube 3 of the optical fiber unit formedical examination and treatment, which is taken out from the lightsource device main body, is inserted into two sets of roller pairs 182,183 of the guide part 108 attached to the second joint part 104.Furthermore, the probe 4 of the optical fiber unit for medicalexamination and treatment is inserted between the gripping members 174,175 of the probe retaining part 107, wherein by operating the knob 178,the probe 4 of the optical fiber unit is retained between the grippingmembers 174, 175. With the above procedures, the optical fiber unit formedical examination and treatment can be attached to the arm device foroptical fiber.

From this state, the user of the optical fiber unit for medicalexamination and treatment loosens the locking member 134 of the firstflexible arm part 103 once, and fixes the locking member 134 afterpulling out the inner pipe 133 from the outer pipe 132 and inserting thesame thereinto, whereby he is able to set the first flexible arm part103 to any desired length. Furthermore, the second flexible arm part 105can be set to any desired length. Since the flexible guide tube 3 isinsertably nipped between two sets of roller pairs 182, 183 of the guidepart 108, the flexible guide tube 3 can move, following the elongationand contraction of the first flexible arm part 103 and the secondflexible arm part 105 even though the first flexible arm part 103 andthe second flexible arm part 105 are contracted and elongated with theprobe 104 retained in the probe retaining part 107.

Next, when the user of the optical fiber unit for medical examinationand treatment holds the probe 4 and moves the same horizontally, thesecond joint part 104 will be rotated in the direction opposite thelocking direction of one-way clutch to cause the second flexible armpart 105 to rise in the horizontal direction with a comparatively weakforce and to move to any desired position. Accordingly, since the secondjoint part 104 is locked by the one-way clutch 144 if his hand isreleased at the position where the second flexible arm part 105 moved,the second flexible arm part 105 retains its stopped position againstits gravity, whereby the probe 4 can be retained with its position kept.

In a case where a user of the optical fiber unit for medical examinationand treatment moves the first flexible arm part 103 in the horizontaldirection so as to make the same fall down, since a locking force isactuated onto the first joint part 102 by the one-way clutch 124, it isnecessary to move the first flexible arm part 103 with a comparativelystrong force. However, it is possible to keep the posture of the firstflexible arm part at the position where the same has been pressed andmoved.

Furthermore, if a force in the rotation direction is given to the firstflexible arm part 103 at an optional posture of the first flexible armpart 103, it is possible for the first flexible arm part 103 to turn 360degrees centering around the shaft 111 of the base end part 101 alongwith the first joint part 102. Similarly, if a force in the rotationdirection is given to the second flexible arm part 105 at an optionalposture of the second flexible arm part 105, it is possible for thesecond flexible arm part 105 to turn 360 degrees centering around theshaft of the first flexible arm part 103 along with the second jointpart 103.

Therefore, since the optical fiber unit for medical examination andtreatment can be easily operated, following the arm device for opticalfiber, the user can comparatively easily allow the probe 4 to come nearan affected part.

On the other hand, in a case where the optical fiber unit for medicalexamination and treatment and arm device for optical fiber are reset totheir initial position shown in FIG. 2 after the optical fiber unit isused, first the user of the optical fiber unit holds the probe 4 in hishand and moves the same so as to come near the base end part 101,wherein the second joint part 104 can turn against the locking by theone-way clutch 144, the angle between the second flexible arm part 105and the first flexible arm part 103 is made narrow, and it is possibleto reset the second flexible arm part 105 to such a state where thesecond flexible arm part 105 is approached to the first flexible armpart 103.

Next, if a force is given to the first flexible arm part 103 in itserecting direction, the first flexible arm part 103 can be reset to theerecting position with a comparatively weak force, wherein the opticalfiber unit for medical examination and treatment and arm device foroptical fiber can be reset to the initial positions shown in FIG. 2.

FIG. 10 and FIG. 11 are respectively a side elevational view and across-sectional view each showing a construction of a first joint part102′ which is a modified example of the first joint part 102 shown inFIG. 2 and FIG. 5. The first joint part 102′ of this example is composedof an axial fixing member 191 rotatably attached to the shaft 111 of thebase end part 101, a hollow shaft 193, attached to the axial fixingmember 191 via a screw 192, having a notch 193 a for one-way clutch onits side circumferential surface, a bearing member 195 rotatably fittedto the hollow shaft 193 via a sintered ring 194, an angle regulating pin196 implanted in the bearing member 195 and inserted into an arcuategroove 191 a of the axial fixing member 191, a rotating plate member 199rotatably attached to the hollow shaft 193 by a screw 197 and fixed viaa sintered ring 198, a roller 200 for one-way clutch, which is idlyfitted into the notch 193 a, a lock cancelling pin 201 implanted in therotating plate member 199 for cancelling the locking of the one-wayclutch in engagement with the roller 200, an arm 202 fixed at therotating plate member 199, a ball knob 203 attached to the arm 202, anda reset spring 204 for resetting the rotating plate member 199 to theinitial position.

The first joint part 102′ of this example, which is constructed asdescribed above, is such that the locking effected by the one-way clutchconsisting of the notch 193 a of the hollow shaft 193 and the roller 200can be manually cancelled by providing the same with a ball knob 203.That is, although the bearing member 195 can be rotated without any loadwhen the same is rotated in the direction of arrow “a”, the roller 200is engaged in the notch 193 a to effect the locking if the bearingmember 195 is attempted to rotate in the direction of arrow “b”. Whenthe ball knob 203 is pushed up from this locked state, the lockcancelling pin 201 is engaged with the roller 200 via the arm 202 androtating plate member 199, thereby cancelling the engagement of theroller 200 with the notch 193 a of the hollow shaft 193, wherein thelock comes off. Therefore, since both the axial fixing member 191 andthe bearing member 195 are made free, it is possible to comparativelyeasily shift down the first flexible arm part 103 to any desiredinclination position. And if your hand is released from the ball knob203 at a position where the first flexible arm part 103 is inclined, therotating plate member 199 is reset by a restoration resiliency of thereset spring 104 to cause the roller 200 to be again engaged in thenotch 193 a and to cause the one-way clutch to be locked again.Furthermore, in a case where the first flexible arm part 103 is reset tothe initial erect position, since the lock of the one-way clutch doesnot operate, it is possible to reset the first flexible arm part 103 tothe erect position with a comparatively weak force.

Furthermore, an arm device for optical fiber according to theabovementioned preferred embodiment is described on the basis of theexample in which an optical fiber unit for medical examination andtreatment shown in FIG. 1 is attached thereto. An optical fiber unitattached to the arm device for optical fiber is not necessarily limitedto that for medical examination and treatment. Various kinds of opticalfiber units for industrial applications, medical diagnosis, etc. may beattached thereto for use.

What is claimed is:
 1. An optical fiber unit for use in medicalexaminations and treatments by irradiating light including infrared raysemitted from a light source onto an affected part, said unit comprising:a flexible optical fiber light guide formed from a bundle of opticalfibers and provided for guiding the emitted light therethrough, whereinthe tip portion of said optical fiber bundle forming said optical fiberlight guide comprises a tapered conduit part in which the diameter ofeach optical fiber is gradually made smaller toward the tip thereof, andwherein said tapered conduit part condenses said light to irradiate saidlight onto an affected part.
 2. An optical fiber unit for medicalexamination and treatment as set forth in claim 1, further comprising arectilinear polarization plate positioned distally to the tip of thetapered tip portion, wherein said rectilinear polarization platerectilinearly polarizes said light irradiated from the tip of saidtapered tip portion of said optical fiber light guide.
 3. An opticalfiber unit for medical examination and treatment as set forth in claim2, wherein the rectilinear polarization plate is effective to straightena light polarization plane of a wavelength band of about 0.6 to about1.6 μm so as to increase therapeutic effects achieved upon treatmentwith said optical fiber unit.
 4. An optical fiber unit for use inmedical examinations and treatments by irradiating light includinginfrared rays emitted from a light source onto an affected part, saidunit comprising: a flexible optical fiber light guide formed from abundle of optical fibers, each of which comprises a core and claddinghaving different refraction indexes, each core guiding the emitted lightthrough said core, wherein the tip portion of said optical fiber bundleforming said optical fiber light guide comprises a tapered conduit partthat is formed of said optical fibers and in which the diameter of eachoptical fiber and the diameter of each core thereof are gradually madesmaller toward the tip thereof; and wherein each optical fiber of saidtapered conduit part condenses said light to irradiate said light fromthe tip end plane thereof onto an affected part.